Information processing apparatus, controlling method thereof, and program

ABSTRACT

The present disclosure is directed to switch a voltage to be supplied to a power source switch in accordance with a state of a power source of an apparatus and restrain power consumption of the power source switch.

BACKGROUND OF THE INVENTION Field of the Invention

The present disclosure relates to an information processing apparatus, acontrolling method thereof, and a program.

Description of the Related Art

There is known an MFP serving as an information processing apparatusthat executes various processes such as a copy process, a print process,and a FAX process. An information processing apparatus such as a multifunction peripheral (MFP) includes a power source switch for switchingon or off a power source of the apparatus, and, when a user operates thepower source switch, supply of power to the apparatus is started orstopped.

Japanese Patent Laid-Open No. 2012-115995 discloses that a power sourceswitch and a DCDC converter are arranged on an identical power sourceline. In a case where the power source switch 35 is on, power issupplied to a DCDC converter 31 from an AC adapter 2 via the powersource switch 35. Meanwhile, in a case where the power source switch isoff, power is supplied to the power source switch 35 from the AC adapter2, but supply of power to the DCDC converter 31 is stopped.

In the above-mentioned power source switch, a minimum load current isdefined to guarantee switching on/off operation, and, in order to causethe minimum load current to flow when the power source switch is turnedon, it is necessary to supply power even in a state in which the powersource is off.

SUMMARY OF THE INVENTION

An information processing apparatus disclosed in the present disclosureincludes, a first converter configured to convert AC power to DC powerof a first voltage, a power source switch operated by a user, a secondconverter configured to, after the power source switch is switched on,convert the DC power of the first voltage converted by the firstconverter to DC power of a second voltage lower than the first voltage,and a first power source controlling unit configured to change, fromeither the first converter or the second converter, power supplied tothe power source switch, in accordance with a state of a power source ofthe information processing apparatus.

Further features of the present disclosure will become apparent from thefollowing description of exemplary embodiments (with reference to theattached drawings).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing an information processingapparatus according to an embodiment of the present disclosure.

FIG. 2 is a block diagram showing an internal configuration of acontroller unit according to an embodiment of the present disclosure.

FIG. 3 is a block diagram showing an internal configuration of apower-source-switch power supply unit and a controller power supply unitaccording to an embodiment of the present disclosure.

FIG. 4 is a timing chart showing operation of a power-source-switchpower supply unit and a controller power supply unit at the time ofstarting up the information processing apparatus according to anembodiment of the present disclosure.

FIG. 5 is a timing chart showing operation of a power-source-switchpower supply unit and a controller power supply unit at the time ofturning off a power source of the information processing apparatusaccording to an embodiment of the present disclosure.

DESCRIPTION OF THE EMBODIMENTS Embodiment

Hereinafter, this embodiment will be described in detail with referenceto the drawings. In the following embodiment, an MFP will be exemplifiedas an information processing apparatus. However, the informationprocessing apparatus is not limited to the MFP and may be an informationprocessing apparatus such as an SFP or a PC.

FIG. 1 is a schematic diagram showing a configuration of an MFP 100 inthis embodiment.

In FIG. 1, the MFP 100 includes a controller unit 101, an AC plug 102, apower source unit 103, a power source switch 104, an operation unit 105,and a power supply unit 106. The MFP 100 further includes a scanner unit107 and a printer unit 108. The controller unit 101 is connected to thepower source unit 103, the power source switch 104, the operation unit105, the power supply unit 106, the scanner unit 107, and the printerunit 108. The AC plug 102 is connected to the power source unit 103.

The MFP 100 can execute various processes such as a scanning process anda print process. The controller unit 101 comprehensively controls thewhole MFP 100. The AC plug 102 is inserted into an external outletserving as a power source. Commercial AC power is supplied to the powersource unit 103 from the external outlet via the AC plug 102. The powersource unit 103 converts AC power supplied from the external outlet toDC power and supplies the power to the controller unit 101 and the powersupply unit 106. The power source switch 104 is a switch for allowing auser to control start-up and stop of the MFP 100. The power sourceswitch 104 is, for example, a rocker switch that physically maintains astate showing start-up or stop of the MFP 100. Note that, in thisembodiment, power is supplied to the power source switch 104 and theoperation unit 105 via the controller unit 101.

The power source switch 104 notifies the controller unit 101 that theMFP 100 is in an activated state (on state) or a shutdown state (offstate). The operation unit 105 includes a display unit and an operationkey (not shown) and accepts an instruction to execute each process inputfrom the user. The scanner unit 107 reads a document placed on a platen(not shown) and generates image data. The printer unit 108 prints on asheet of paper on the basis of image data or the like generated in thescanner unit 107. The power supply unit 106 supplies power supplied fromthe power source unit 103 to the scanner unit 107 and the printer unit108. Whether or not the power supply unit 106 supplies power to theprinter unit 108 and the scanner unit 107 is controlled by a CPU 204 ofthe controller unit 101.

FIG. 2 is a block diagram schematically showing an internalconfiguration of the controller unit 101 in FIG. 1.

In FIG. 2, the controller unit 101 includes a controller power supplyunit 201, a voltage conversion unit 202, a power-source-switch powersupply unit 203, the CPU 204, a memory 205, an HDD 206, and an imageprocessing unit 207.

The controller power supply unit 201 monitors a state of the powersource switch 104 and, when the power source switch is changed from theoff state to the on state, supplies DC power supplied from the powersource unit 103 to the voltage conversion unit 202. Because DC power issupplied to the voltage conversion unit 202 from the power source unit103, the CPU 204 starts to execute a start-up program and executes astart-up process of the MFP 100. As described above, the controllerpower supply unit 201 controls power to be supplied to a control unitincluding a CPU, a memory, a DHH, and the like.

The voltage conversion unit 202 converts a voltage of DC power suppliedfrom the controller power supply unit 201 to a voltage to be supplied tothe CPU 204, the memory 205, the HDD 206, the image processing unit 207,and the power-source-switch power supply unit 203.

DC power output by the voltage conversion unit 202 is supplied to theCPU 204, the memory 205, the HDD 206, the image processing unit 207, andthe power-source-switch power supply unit 203. Note that the voltageconversion unit 202 converts DC power supplied from the power sourceunit 103 to DC power having a voltage lower than that of theabove-mentioned DC power and outputs the converted DC power.

The power-source-switch power supply unit 203 is connected to the powersource unit 103, the power source switch 104, and the voltage conversionunit 202. The power-source-switch power supply unit 203 supplies DCpower supplied from the power source unit 103 or DC power supplied fromthe voltage conversion unit 202 to the power source switch 104. Thepower-source-switch power supply unit 203 controls power to be suppliedto the power source switch. Operation of the power-source-switch powersupply unit 203 will be described below with reference to FIG. 3.

The CPU 204 is connected to the operation unit 105, the power supplyunit 106, the memory 205, the HDD 206, and the image processing unit207. The CPU 204 executes programs stored on the HDD 206 and performsvarious kinds of control. The CPU 204 controls whether to supply powerto the printer unit 108 and the scanner unit 107 from the power supplyunit 106. For example, in a case where the MFP 100 transitions to asleep mode that consumes less power than a standby mode whilemaintaining the power source switch 104 in an on state, the CPU 204instructs the power supply unit 106 to stop supply of power to theprinter unit 108 and the scanner unit 107. With this, it is possible torestrain power consumption of the MFP 100 in the sleep mode. In thisembodiment, even in a case where the MFP 100 is in the sleep mode, thevoltage conversion unit 202 generates DC power, and thepower-source-switch power supply unit 203 supplies DC power output bythe voltage conversion unit 202 to the power source switch 104. Withthis, even in a case where the MFP 100 is in the sleep mode, it ispossible to supply DC power generated by the voltage conversion unit 202to the power source switch 104, instead of supplying DC power generatedby the power source unit 103 to the power source switch 104.

The memory 205 is a volatile memory and is a main memory that storesdata or the like generated by execution of each program of the CPU 204.The HDD 206 stores the programs executed by the CPU 204, settinginformation regarding the MFP 100, and the like. The image processingunit 207 performs image processing such as color space conversion withrespect to image data generated in the scanner unit 107 and outputs theconverted image data to the printer unit 108. When the MFP 100 isstarted up, DC power output from the voltage conversion unit 202 issupplied to the CPU 204. In response to the supply of power, the CPU 204reads a program stored on the HDD 206, executes the program, and startsa start-up process of the MFP 100.

FIG. 3 is a block diagram showing an internal configuration of thepower-source-switch power supply unit 203 and the controller powersupply unit 201 in FIG. 2.

The power-source-switch power supply unit 203 includes an FET 301, atransistor 302, a digital transistor 303, and diodes 310 and 311. TheFET 301 is a switching element that switches whether to supply DC powersupplied from the power source unit 103 to the power source switch 104.A source terminal of the FET 301 is a terminal to which DC power 309supplied from the power source unit 103 is supplied. A gate terminal ofthe FET 301 is connected to a collector terminal of the transistor 302.That is, the FET 301 is switched on/off in accordance with on/offoperation of the transistor 302. A drain terminal of the FET 301 isconnected to the power source switch 104 via the diode 310. The FET 301is turned on when a potential difference between the gate and the sourceis equal to or more than a threshold value. Note that the FET 301 is ap-channel power MOSFET in this embodiment.

A base terminal of the transistor 302 is connected to a collectorterminal of the digital transistor 303. The collector terminal thereofis connected to the gate terminal of the FET 301. An emitter terminalthereof is grounded. The transistor 302 is turned on when a voltageapplied to the base is equal to or more than a threshold value. Thetransistor 302 is switched on/off in accordance with on/off operation ofthe digital transistor 303.

A base terminal of the digital transistor 303 is connected to DC power308 supplied from the voltage conversion unit 202. The collectorterminal thereof is connected to the base terminal of the transistor302. An emitter terminal thereof is grounded. The digital transistor 303is turned on when a voltage applied to the base is equal to or more thana threshold value. That is, the digital transistor 303 is switchedon/off on the basis of a change in output from the voltage conversionunit 202.

Note that the gate terminal of the FET 301 and the base terminal of thetransistor 302 are subjected to a pull-up process by using the DC power309 supplied from the power source unit 103.

DC power 306 of the power source switch 104 is connected to the drainterminal of the FET 301 via the diode 310 and is also connected to theDC power 308 supplied from the voltage conversion unit 202 via the diode311.

The controller power supply unit 201 includes an FET 304, a digitaltransistor 305, and a load resistor 312. The FET 304 is a switchingelement that switches whether to supply the DC power 309 supplied fromthe power source unit 103 to the voltage conversion unit 202. A sourceterminal of the FET 304 is connected to the DC power 309 supplied fromthe power source unit 103. A gate terminal of the FET 304 is connectedto a collector terminal of the digital transistor 305, and a drainterminal thereof is connected to the voltage conversion unit 202. Thatis, the FET 304 is switched on/off on the basis of switching on/off ofthe digital transistor 305. Note that the FET 304 is a p-channel powerMOSFET in this embodiment.

A base terminal of the digital transistor 305 is connected to a powersource switch signal 307 supplied from the power source switch 104. Acollector terminal thereof is connected to the gate terminal of the FET304. An emitter terminal thereof is grounded. The digital transistor 305is switched on/off on the basis of a signal input from the power sourceswitch 104 via the power source switch signal 307. In this embodiment,in a case where the power source switch 104 is turned on and the powersource switch signal 307 is H (High), the digital transistor 305 isturned on.

Note that the gate terminal of the FET 304 is subjected to a pull-upprocess by using the DC power 309 supplied from the power source unit103. The load resistor 312 is a load resistor for causing a necessaryminimum load current to flow to the power source switch 104.

Next, operation of the power-source-switch power supply unit 203 and thecontroller power supply unit 201 at the time of turning on the powersource switch in this embodiment will be described with reference toFIG. 4. FIG. 4 is a timing chart showing processes of thepower-source-switch power supply unit 203 and the controller powersupply unit 201 at the time of turning on the power source switch.

Before the AC plug is inserted into the external outlet, the powersource switch is in an off state, and all the FET 301, the transistor302, and the digital transistor 303 of the power-source-switch powersupply unit 203 are in an off state. Further, the FET 304 and thedigital transistor 305 of the controller power supply unit 201 are alsoin an off state.

First, when the user inserts the AC plug 102 into the external outlet,supply of AC power to the power source unit 103 from the external outletvia the AC plug 102 is started (t0).

When AC power is supplied from the external outlet, the power sourceunit 103 converts the AC power to DC power and starts to output the DCpower 309 (t1).

When supply of the DC power 309 is started, the DC power is applied tothe base terminal of the transistor 302 of the power-source-switch powersupply unit 203, and the transistor 302 is switched from the off stateto an on state. When the transistor 302 becomes the on state and acurrent flows between the collector and the emitter of the transistor302, a potential difference is generated between the source and the gateof the FET 301, and the FET 301 is switched from the off state to an onstate (t2). With this, the DC power 309 output from the power sourceunit 103 is input to the power source switch 104 via the diode 310 andthe DC power 306.

At this time, the collector terminal of the digital transistor 303maintains the off state. Further, the FET 304 and the digital transistor305 of the controller power supply unit 201 also maintain the off state.

As described above, in a case where the AC plug 102 is plugged in whilethe power source switch 104 is being in the off state, the DC power 309output by the power source unit 103 is applied to the power sourceswitch 104.

Next, operation after the user performs on operation of the power sourceswitch 104 will be described. At t3, the user changes the state of thepower source switch 104 to an on state. In response to the change of thestate of the power source switch 104 to the on state, the DC power 306output from the power source unit 103 is input to the power sourceswitch signal 307 via the power source switch 104. Then, a power sourcevoltage input to the power source switch signal 307 is applied to thebase terminal of the digital transistor, and the digital transistor 305is switched to an on state (t4).

When the digital transistor 305 is switched to the on state, a potentialdifference is generated between the source terminal and the gateterminal of the FET 304, and the FET 304 is switched to an on state(t5). When the FET 304 becomes the on state, the DC power 309 outputfrom the power source unit 103 is supplied to the voltage conversionunit 202 via the FET 304. The voltage conversion unit 202 outputs the DCpower 308 having a voltage lower than that of the DC power 309 suppliedfrom the power source unit 103. The DC power 308 is supplied to the CPU204, the memory 205, the HDD 206, the image processing unit 207, and thelike. Further, the DC power 308 is applied to the base terminal of thedigital transistor 303 of the power-source-switch power supply unit 203.Because of application of the DC power 308, the digital transistor 303is changed to an on state (t7).

In response to the change of the state of the digital transistor 303 tothe on state, a base potential of the transistor 302 is reduced, and thetransistor 302 becomes the off state (t8). When the transistor 302becomes the off state, no potential difference is generated between thesource terminal and the gate terminal of the FET 301, and the FET 301becomes the off state (t9). When the FET 301 becomes the off state,supply of the DC power 309 output from the power source unit 103 to thepower source switch 104 is stopped. With this, in a case where the powersource switch 104 is in the on state, it is possible to supply DC powerhaving a voltage lower than that of output from the voltage conversionunit 202 to the power source switch 104, instead of supplyinghigh-voltage DC power output from the power source unit 103 to the powersource switch 104. With this, in a case where the MFP 100 is in the onstate, it is possible to restrain power consumption of the power sourceswitch 104.

FIG. 5 is a timing chart showing operation of the power-source-switchpower supply unit 203 and the controller power supply unit 201 at thetime of plugging out the power source in this embodiment. In a casewhere the power source switch 104 is in the on state, the FET 301 andthe transistor 302 of the power-source-switch power supply unit 203 areoff and the digital transistor 303 thereof is on. Meanwhile, both thedigital transistor 305 and the FET 304 of the controller power supplyunit 201 are on. At t10, the user turns off the power source switch 104.Then, a voltage of the power source switch signal 307 is reduced, andthe digital transistor 305 becomes the off state (t11). When the digitaltransistor 305 transitions to the off state, a potential differencebetween the source and the drain of the FET 304 is reduced, and the FET304 becomes the off state (t12).

When the FET 304 becomes the off state, DC power is not supplied to thevoltage conversion unit 202, and the DC power 308 is reduced. Then, thedigital transistor 303 transitions to the off state (t13). In responseto the transition of the state of the digital transistor 303 to the offstate, the transistor 302 becomes the on state (t14). When thetransistor 302 is turned on, a potential difference is generated betweenthe source and the drain of the FET 301, and the FET 301 is turned on(t15). With this, the DC power 309 output by the power source unit 103is supplied to the DC power 306 of the power source switch 104. With theabove-mentioned operation, when the power source switch 104 is turnedoff, it is possible to switch DC power supplied to the power sourceswitch 104 from a power source voltage output by the voltage conversionunit 202 to DC power output by the power source unit 103. With this, itis possible to supply DC power to the power source switch 104 even in acase where the power source switch 104 is in the off state.

Further, when the power source is plugged out at t17, output from thepower source unit 103 is reduced, and the transistor 302 is turned offaccordingly (t18).

Thereafter, the FET 301 also becomes the off state (t19).

As described above, in this embodiment, a source of supply of power tothe power source switch 104 is changed between when the power sourceswitch is in the on state and when the power source switch 104 is in theoff state, and when the power source is on, power is supplied to thepower source switch at a lower voltage. With this, it is possible torestrain power consumption of the power source switch 104 when the powersource switch is in the on state. For example, in a case where the DCpower 309 is 12 V, the DC power 308 is 5 V, and the minimum load currentof the power source switch 104 is 1 mA, 12 mW is consumed if DC powersupplied to the power source switch 104 is not switched and the DC power309 is continuously supplied. Meanwhile, when DC power supplied to thepower source switch 104 is switched and the DC power 308 is supplied, 5mW is consumed. As described above, it is possible to restrain powerconsumption of the power source switch 104.

According to the embodiment of the present disclosure described above,it is possible to reduce power consumed in the power source switch 104and the load resistor 312 by switching DC power flowing to the powersource switch 104 to the DC power 308 having a voltage lower than thatof the DC power 309 supplied from the power source unit 103.

Additional Embodiment

Note that, in this embodiment, DC power to be supplied to the powersource switch 104 is switched between DC power output by the powersource unit and DC power output by the voltage conversion unit by usinga voltage of DC power output by the voltage conversion unit. The CPU 204may control the power-source-switch power supply unit 203 after supplyof power to the CPU 204 is started. The CPU 204 may execute a start-upprogram of the MFP 100 and perform control so that power to be suppliedto the power source switch 104 is switched from the DC power 309 outputfrom the power source unit 103 to the DC power 308 output from thevoltage conversion unit 202. Further, an interrupt signal may be inputto the CPU 204 in response to transition of the state of the powersource switch 104 to the on state, and the CPU 204 may switch a path ofsupply of power to the power source switch 104 on the basis of theinterrupt signal.

The present disclosure is also achieved by executing the followingprocess.

Specifically, the following process is such that software (program) thatachieves a function of the above-mentioned embodiment is supplied to asystem or an apparatus via a network or various storage media, and acomputer (or CPU, MPU, or the like) of the system or the apparatus readsa program code and executes a program. In this case, the computerprogram and a storage medium storing the computer program fall withinthe scope of the present disclosure.

In view of the above circumstances, the present disclosure can switch avoltage to be supplied to a power source switch in accordance with astate of a power source of an apparatus and can therefore restrain powerconsumption of the power source switch.

Embodiment(s) of the present disclosure can also be realized by acomputer of a system or apparatus that reads out and executes computerexecutable instructions (e.g., one or more programs) recorded on astorage medium (which may also be referred to more fully as a‘non-transitory computer-readable storage medium’) to perform thefunctions of one or more of the above-described embodiment(s) and/orthat includes one or more circuits (e.g., application specificintegrated circuit (ASIC)) for performing the functions of one or moreof the above-described embodiment(s), and by a method performed by thecomputer of the system or apparatus by, for example, reading out andexecuting the computer executable instructions from the storage mediumto perform the functions of one or more of the above-describedembodiment(s) and/or controlling the one or more circuits to perform thefunctions of one or more of the above-described embodiment(s). Thecomputer may comprise one or more processors (e.g., central processingunit (CPU), micro processing unit (MPU)) and may include a network ofseparate computers or separate processors to read out and execute thecomputer executable instructions. The computer executable instructionsmay be provided to the computer, for example, from a network or thestorage medium. The storage medium may include, for example, one or moreof a hard disk, a random-access memory (RAM), a read only memory (ROM),a storage of distributed computing systems, an optical disk (such as acompact disc (CD), digital versatile disc (DVD), or Blu-ray Disc (BD)™),a flash memory device, a memory card, and the like.

While the present disclosure has been described with reference toexemplary embodiments, it is to be understood that the disclosure is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Application No.2018-241725, filed Dec. 25, 2018, which is hereby incorporated byreference herein in its entirety.

What is claimed is:
 1. An information processing apparatus, comprising:a first converter configured to convert AC power to DC power of a firstvoltage; a power source switch of the information processing apparatusoperated by a user; a second converter configured to, after the powersource switch is switched on, convert the DC power of the first voltageconverted by the first converter to DC power of a second voltage lowerthan the first voltage; and a first control module configured to change,from either the first converter or the second converter, power suppliedto the power source switch, in accordance with a state of a power sourceof the information processing apparatus.
 2. The information processingapparatus according to claim 1, wherein the state of the power source ofthe information processing apparatus indicates that the power sourceswitch is in an on state or an off state.
 3. The information processingapparatus according to claim 2, wherein in a case where the power sourceswitch is in the on state, the first control module supplies power tothe power source switch from the first converter, and, in a case wherethe power source switch is in the off state, the first control modulesupplies power to the power source switch from the second converter. 4.The information processing apparatus according to claim 1, wherein thefirst control module changes a source of supply of power to the powersource switch from the first converter to the second converter on thebasis of a voltage of DC power output by the second converter.
 5. Theinformation processing apparatus according to claim 4, wherein the firstcontrol module supplies power to the power source switch from the firstconverter during a period in which the second converter does not convertthe first voltage to the second voltage.
 6. The information processingapparatus according to claim 1, further comprising: a second controlmodule configured to switch whether to supply the DC power of the firstvoltage output from the first converter to the second converter, whereinthe second control module switches whether to supply the DC power of thefirst voltage output from the first converter to the second converter onthe basis of a voltage supplied via the power source switch.
 7. Theinformation processing apparatus according to claim 1, wherein the firstconverter converts the AC power to the DC power of the first voltage,regardless of a state of the power source switch.
 8. The informationprocessing apparatus according to claim 1, wherein the power sourceswitch is a rocker switch.
 9. The information processing apparatusaccording to claim 1, wherein the DC power of the second voltage issupplied to a controller of the information processing apparatus fromthe second converter.
 10. The information processing apparatus accordingto claim 9, wherein the controller executes a start-up program of theinformation processing apparatus.
 11. An information processingapparatus, comprising: a first converter configured to convert power ofAC power to DC power of a first voltage; a power source switch operatedby a user; and a second converter configured to, after the power sourceswitch is switched on, convert the DC power converted by the firstconverter to DC power of a second voltage lower than the first voltage,wherein DC power to be supplied to the power source switch is changedbetween the DC power of the first voltage output by the first converterand the DC power of the second voltage output by the second converter inaccordance with a state of a power source of the information processingapparatus.
 12. A method of controlling an information processingapparatus including, a power source switch operated by a user, a firstconverter configured to generate first DC power from AC power, and asecond converter configured to, after the power source switch isswitched on, convert DC power of a first voltage converted by the firstconverter to DC power of a second voltage different from the firstvoltage, the method comprising: a power source controlling step ofchanging, from either the first converter or the second converter, powersupplied to the power source switch, on the basis of a state of a powersource of the information processing apparatus.
 13. The method accordingto claim 12, wherein the state of the power source of the informationprocessing apparatus indicates a state of the power source switch. 14.The method according to claim 13, wherein in the power sourcecontrolling step, in a case where the power source switch is on, poweris supplied to the power source switch from the second converter, and,in a case where the power source switch is off, power is supplied to thepower source switch from the first converter.